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Not all knob and tube installations utilized cleats.Ceramic bushings protected each wire entering a metal device box, when such an enclosure was used.
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Loom, a woven flexible insulating sleeve, was slipped over insulated wire to provide additional protection whenever a wire passed over or under another wire, when a wire entered a metal device enclosure, and in other situations prescribed by code.
Other ceramic pieces would typically be used as a junction point between the wiring system proper, and the more flexible cloth-clad wiring found in light fixtures or other permanent, hard-wired devices.
When a generic power outlet was desired, the wiring could run directly into the junction box through a tube of protective loom and a ceramic bushing.
Wiring devices such as light switches, receptacle outlets, and lamp sockets were either surface-mounted, suspended, or flush-mounted within walls and ceilings.